tenacity9 said:
I have an older laptop which I am happy with, but max resolution shown in XP
is 1280x1024. I want to hook up to a 22" external monitor with 1680x1050
native resolution. The grapics card is Intel 82852/82855 GM/GME Graphics
Controller. I don't believe there is an updated Intel driver which increases
the resolution beyond 1280x1024.
Is there any solution to increase the resolution without changing the card,
perhaps through a 3rd party software utility or other means? Any other ideas
will be appreciated.
Information for the chipset.
http://www.intel.com/support/graphics/intel852gm/
"Frequently asked questions.
Supported display modes and resolutions"
http://www.intel.com/support/graphics/sb/CS-022544.htm
"Specifically, Intel graphics drivers support:
* Display modes reported by the monitor’s EDID (Extended Display Information
Data). Only plug and play monitors can provide EDID information to a computer.
* Custom display modes defined within the Video BIOS Table (VBT) by the
computer manufacturer.
* Static modes for non Plug and Play monitors without an EDID. The set of
basic static display modes (at 60Hz and up to 32bpp colors) include
640x480, 800x600, 1024x768, 1280x1024, and 1600x1200.
* If you are unable to use the native resolution of a digital flat panel
display (such as 1920x1080, 1680x1050, 1440x900, etc.), there may be a
problem reading the display's EDID. "
To verify whether the external monitor has an EDID, try this utility.
"... queries the monitor directly ... "
http://www.entechtaiwan.com/util/moninfo.shtm
Entechtaiwan also makes Powerstrip, a utility for defining custom resolutions,
but it works best with ATI and Nvidia desktop cards. Chipsets are harder to
support, and if the chipsets don't support a common API, then it is harder
to define custom formats.
http://www.entechtaiwan.com/util/ps.shtm
Powerstrip has a whole set of FAQ pages, so you can better understand the
limitations.
http://forums.entechtaiwan.com/index.php?board=7.0
So, what are the basic limitations of any hardware ?
1) For VGA, the DAC output bandwidth defines an upper limit, where the
pixels will still be sharp and clear. For modern hardware, this number
has settled at around 400MHz bandwidth, suitable for a pretty big display.
It is likely that cable quality will determine whether the entire 400MHz
bandwidth can be used. VGA quality depends on the transmission media, connectors
and so on, and the VGA 15 pin high density connector is not the best for
that purpose. Manufacturers like Sun, had a better connector for that
purpose, with actual coaxial connectors where required. This is what
VGA should have looked like.
http://www.pacificcable.com/Photos/13W3-Male-Connector.jpg
2) For many years (since I built my own frame buffer for a computer
in early 1980's), the video chips have supported flexible vertical
and horizontal formats. This includes registers to define front porch,
back porch. So my assumption in a GPU, is the only limit boils down to
character orientation (horizontal resolution divisible by 8, vertical
resolution divisible by 2). 1680x1050 meets those rough rules. Some
DVI devices have managed to relax those rules, but those rules are
a good starting point. It is possible for the registers that control
resolution, to have limits, or even for some idiot to fix the resolutions
possible in hardware, but it really makes no practical sense to do that.
Manufacturers in the past, have been scared of allowing video outputs
to define values which can damage a monitor. There were CRT monitors in the
past, with fixed resolutions. Sending them the wrong signals could damage
the monitor (black screen, no longer works). Even some of the multisync
monitors, didn't have protection against out of bounds values, and could
be damaged. As time has passed, multisync monitors have improved, so that
they recognize instantly, when the values are outside what they support.
But that doesn't change the job of the driver writer. They still have to
assume some idiot will dig up a 20 year old VGA CRT monitor, connect it,
damage it, and they complain about it.
And as the chipsets age, the manufacturer's interest in supporting them
wanes. Sometimes, one even has to question whether the manufacturer
really has the depth in their driver writing department, to do a good
job in any case. Even if given an infinite amount of time to fix their
driver.
HTH,
Paul
